Using a polishing wheel to remove the burr and unevenness on the surface of the titanium rod and make the surface of the part reach a bright level is polishing. Polishing is used for the preparation and finishing of coatings (such as nickel, chromium, titanium, titanium alloys, etc.) before the surface treatment of the base metal. The commonly used polishing wheels are made of separate discs such as muslin cloth, silk, and felt.

(1) Grinding wheel and polishing wheel

a. Grinding wheel: The materials for making grinding wheels include felt, leather, woolen cloth, cotton cloth, and special paper. Most of the pieces are folded and assembled, and the pieces are sewn with white thread, fishnet thread, or twine.

b. Polishing wheel: Various cotton cloth, fine felt, leather, and other materials can be used to make a polishing wheel. The hardness is determined by the distance between the sutures and the type of cloth. The smaller the distance between the sutures, the greater the hardness of the polishing wheel.

There are three kinds of polishing wheels that are often used, namely non-stitched type (used for small complex products, small parts, and final finishing), stitched type (polishing of products with simpler shapes), and air-cooled cloth wheel (suitable for polishing large flat surfaces). , Large round tube products, the layout of the latter polishing wheel is more suitable for active polishing machines, also known as louver polishing wheels. It is to sew the polishing cloth into multi-layer thick cloth strips and fix it on the rim of the polishing wheel, as if it were Radial shape, each cloth strip can be rolled independently, so it is extra soft than the usual polishing wheel, and the polishing area is more than 20% wider than the usual polishing wheel area.

(4) Polishing liquid

Polishing with polishing liquid is also known as liquid polishing, that is, using emulsified polishing liquid (rich in abrasives of different particle sizes) on the active polishing machine to replace the traditional solid polishing wheel. The advantages of this approach are as follows:

a. Less waste slag: If the appropriate polishing liquid is added automatically or manually to the polishing machine, there will be no waste slag or dust problems like solid polishing liquid.

b. Simple cleaning: The polishing liquid is full of emulsion with abrasive particles, so it is easy to clean than the solid polishing night.

c. Power saving: The polishing liquid spray device does not need to be repaired for a long time.

d. Extend the service life of the polishing wheel.

(2) Adhesive

Adhesives are required for bonding abrasive grains to grinding wheels and for making polishing pastes. Commonly used binders on grinding wheels are water glass, various glues, and resins. These substances have the properties of melting or sintering at a certain temperature and can bond the abrasive grains after cooling and coagulation. The most commonly used is bone glue. Now take it as an example to describe its bonding method.

After crushing the bone glue, soak it in water until the glue swells, add a certain amount of water (usually the ratio of glue to water is 1:2), and heat the glue tank in water to 60-70 degrees: dissolve, and then put it in the water. Apply glue on the grinding wheel, roll the abrasive with the required particle size immediately after coating, and then put it in an oven to dry for 24 hours at a temperature of about 40 degrees. The binders used to make the polishing liquid are: various semi-solid oils, fats, stearic acid, oleic acid, wax, paraffin, etc.

(3) Polished and polished titanium rods

Abrasive: Abrasive is the main material used to complete the process of cutting and leveling metal surfaces. Any naturally produced or artificially produced ores can be used as abrasives as long as the particles have the cutting ability. In addition to this, the abrasive should have an internal structure (resistance) or cohesion in order to ensure that the formed abrasive crystals are stable against shear forces as they become dull; at the same time, the shape of the particles is also important, as in hardness Under certain conditions, the abrasive of spherical particles is not as strong as the abrasive of sharp-edged particles.

① Polishing abrasives: Commonly used polishing abrasives include artificial emery, corundum, and emery. The hardness (9.2) of artificial diamond grit (silicon carbide) is higher than that of corundum (9.0) and close to the diamond, its specific gravity and resistance are lower than those of corundum, and it has a bright purple-black appearance. Its particles have very sharp edges. This abrasive is basically selected for rough grinding because the particles of this abrasive are more brittle than corundum, so it is usually used to process workpieces with low tensile strength, such as brass and cast iron, hard aluminum, and hard aluminum alloy. and other parts.

There are two kinds of abrasives, artificial corundum, and natural corundum. Natural corundum is rich in alumina with a mass fraction of 90%-95%, and artificial corundum is mostly used in practical production. Corundum has better resistance than artificial emery, and it is suitable for polishing metal parts that are tougher and have greater tensile strength, such as manganese bronze, titanium alloy, cobalt-chromium-tungsten-molybdenum alloy parts, and so on.

Carborundum (hetero-corundum) is a fine-grained natural rock rich in 60%-70% alumina and 30%-35% iron oxide and impurities of quartz and cinnamate, gray-red to black in appearance . It can be applied to the polishing of all metals, especially resistant metals. Therefore, emery abrasives are widely used in polishing the surface. Regarding the abrasives on the belt mill, in addition to the above-mentioned types, the newly selected abrasives are composed of alumina and zirconia. It is durable under light pressure and cuts quickly under heavy pressure.

②Abrasives for polishing: Alumina, chromium oxide, and iron oxide are commonly used polishing abrasives. Alumina is calcined from aluminum hydroxide. Chromium oxide is a very hard and sharp dark green powder, which is mainly used for polishing chromium and carbide workpieces with very high hardness.